Ask HN: Importance of a Confirmation Email

I'm working on the registration form for a web app and am considering various ways to do it. There are essentially two major steps:

1. Customer enters email and chooses a password

2. Customer pays

The email and password combination would let the customer access the site on future visits, assuming they complete the payment.

My original plan was to send their email a confirmation link after the first step and that link would validate the email address and bring them to the payment page. However, it occurred to me that I might be able to skip the confirmation email all together; go straight from step 1 to step 2.

I don't really see any major downsides to doing it this way. Typos could be minimized by having them enter the email twice. Worst case, they could always email support (me) and I'd help them work through their problem. Seems like the small support tradeoff would easily worth the higher completion rates.

Not sure if I'm missing any major considerations... Could a malicious person take advantage of this system?